Abstract

A new series of organic superconductors is reported: λ-type salts of bis(ethylenedithio)tetraselenafulvalene (BETS) with mixed halide gallium anions. Their preparation and properties are described, with particular emphasis on the electrical resistivity. A strong correlation is observed between the superconducting transition temperature Tc and the unit cell volume, which should enable the superconducting transition to be investigated systematically and facilitate the design of new organic superconductors with enhanced Tc.